Process of making silicon nitrid.



@EATHiPfiENT enrich ALF SINDING-LARSEN, OE CHIR-IS'IIANIA, NORWAY.

PROCESS OF MAKING- SILICON NITRID.

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No Drawing.

To all whom 171: may concern."

. e it known that l, Am SINDING-LARSEN, a .ibject the King of Norway,residing at (ll ristiania, Norway, have invented certain new and usefulimprovements in Processes of lilanufactru'ing Silicon Nitrid; and I dohereby declare the following to be a full, clear, and exact descriptionof the invention,

suchas will enable others skilled in the art to which it appertains tomake and use the same.

The present ii'ireution has ifLl its object a process or manufacturingsilicon nitrid, accor-din to which this latter product is obtained in afinely 'rided state at the same time as a complete ll; reformation ofthe silicon into nitrid is secured.

As is well known pure s1" temperatures very casi ly con'ibiee gen, butit is very dillicult to obtain a quantitative transtoequation intonitrid, as only the surface of the silicon will be acted upon owing tothe fact, that the nitrid already formed to a certain extent protectsthe subjacent part of the silicon against further action. it the siliconhowever is dissolved in a or the like, with which it forms an alley orcompound, which is fluid at the temperature, at which the reaction takesplace between silicon and nitrogen, for instance silico-iron,alui'niniuni silicid or another silicid, and this alloy or compound at asuitable temperature treated with a current of nitrogen, the entireamount of silicon will be transformed into nit d, which '3 produced insuch a finely diy that it is capable of being directly ployed as amanure, or ifdesired it could be ployed for the manufacture of oxideoin' gen and through this latter into other 11' .7

gen compounds, while the silica oluained by ,the oxidation process canagain be worked on ni'l'ridi By this process a silicid oi? a n'ictalcould also be freed from its content of silicon, so that for instancefrom aluminium silicid such obtained by totally reducing aluminiumsilicates, in addition to the valuable nitrid of silicon could beobtained 1netallic aluminium.

This process, which may be carried out in an electric inductionorresistancefurmlce of such a construction as to allow of the supply andpreheating of the current of nitrogen and also if desired of employingpressure, maybe conducted in such a manner that the other component ofthe silicid for Specification of Letters Patent.

Application filed February l0, 1509.

Patented June 21, 1910.

Serial No. 477.138.

instance aluminium is distilled over into a suitable vessel.

The following is an example of how the process may he carried out. inalloy of alun'iiniu n and silicon, containing equal parts of eachcomponent and which may have been. produced by totally reducing analuminium silicate, is heated in a converter shaped furnace lined withsilicon nitrid and kept at a temperature of about 2000 centigrade.'lhrough the fused rloy or melt is then. drawn a currentof nitrogen,which. keeps the bath violently stirred at the same time the ilicou.content of the bath grail ally coin with the nitrogen forming siliconnitrid, for instance oi the formula con nu id formedflihe temperature isowered to aooui 900 ceutip nule and a mixture oi" chloride on sodium andpotassium is added as a flux, into which the ali'uniniuin sinks to thebottom and melts togetlvr while the uitrid remains suspended in the slagor flux. If it is found that the alun'iiniuiu still contalus silicon andit is desired to obtain it. in a pure state the above l'lc rrihedtreatment is repeated. The silicon nilrid then separated from the flux,in which it is suspended, either by lixiviatiug the chlorids and thenfiltering the obtained solution or by Volatiliziug the chlorids. Theiluxing materials may of course be rccoveird and repeatedly employed. iithe aluminiiun silicate our plorcd in producing the aluminium silironalloy is not quite pure or it the nitrogen treatment is not carried verytar, the resulting-aluminium will contain a quantity of iron and siliconas-inipuritics. To be obtained in quite a pure state the aluminium mayin this case be subjected to a distilling process (optionally atractional distillation or alloy of a metal and silicon to a temperaturesufficient to react on nitrogen andv introducing a current of nitrogenin contact therewith, said compound being liquid at the temperature atWhich the reaction takes place.

2. The process of manufacturing silicon nitrid which comprises heating acompound or alloy of a metal and silicon that becomes liquid at thereacting temperature of nitrogen and silicon, and conducting nitrogen incontact Withsaid liquid compound or alloy and evaporating the metal.

3. The process of manufacturing silicon nitrid which comprisesconducting heated nitrogen into-contact With a melt of a compound oralloy of a metal and silicon.

4. The process of manufacturing silicon nitrid which comprisesconducting nitrogen into contact with a melt of aluminium silicid anddistilling the aluminium therefrom.

5. The process of manufacturing silicon nitrid which comprisesconducting heated nitrogen into contact With a melt of aluminium silicidand distilling the aluminium therefrom.

In testimony that I claim the foregoing as my invention, I have signedmy name in presence of two subscribing Witnesses.

ALF SINDING-LARSEN.

Witnesses HENRY BoRDEWIon, M. ALGER.

